Issue: You are about to change the energy analysis mode. Conceptual mass and building element energy analytical models cannot co-exist. See Energy Analysis for Autodesk® Revit® for more information.
Solution: Click Change to Building Element Mode if you want to use building elements as the basis for the energy simulation. If you change the energy analysis mode to Building Element Mode, an existing conceptual mass energy analytical model will be deleted. Select Cancel to remain in Conceptual Mass mode.